The present invention relates to a process and system for controlling a windshield wiper, particularly on a motor vehicle, wherein a rain sensor is located on the windshield to be wiped and in the region of the windshield wiper to give off a sensor signal as a function of the amount of moisture. The sensor signal is detected cyclically and, when a given degree of moisture is reached in a measurement cycle, the system produces a triggering signal and controls the windshield wiper.
Means for controlling windshield wipers are known in which the amount of moisture on the windshield is detected by sensors arranged on the windshield.
When a predetermined amount of moisture is reached on the windshield, the windshield wiper motor is automatically turned on. For optimal vision, it is, however, important to adapt the operation of the windshield wiper to the prevailing intensity of the rain, which can be effected by connection and disconnection, change of the interval between individual wiping processes, change of the speed and/or switching between intermittent operation (individual wipe) or continuous operation (continuous wiping).
In known processes, a trigger signal for the windshield wiper is given off depending on whether the sensor signal has reached or exceeded a predetermined threshold value. In this case, the threshold value represents the transition from a wet to a dry windshield. In the case of a fine rain or mist, the windshield wiper of the vehicle is covered with moisture, but this threshold value is not exceeded in view of the fact that the amplitude of the signal is not changed substantially. The windshield wiper signal is not given off.
Optical vision on the part of the driver of the vehicle, however, requires actuation of the windshield wiper.